# MatchHandler

A route output or parameter-dependent output function.

## Signatures

```ts
export type MatchHandler<Params, A, E, R> = Fx.Fx<A, E, R> | Stream.Stream<A, E, R> | Effect.Effect<A, E, R> | A | ((params: RefSubject.RefSubject<Params>) => Fx.Fx<A, E, R> | Stream.Stream<A, E, R> | Effect.Effect<A, E, R> | A);
```

## Why

Handlers can observe renderer-independent parameter RefSubjects and return any supported producer.

## Ownership and lifetime

The type itself owns nothing. When selected, the executor invokes the function once for that handler identity and runs its normalized Fx in the route Scope.